I am new to sim racing and I'm loving RaceRoom. I bought a new mini PC from GMKtec (as I travel between two countries). I'm very happy with it. It has 32GB RAM and an AMD Ryzen 9 8945HS processor. It has an onboard AMD Radeon 780M GPU. The GPU is described as: 12 cores, 2800MHz, AMD RDNA 3 architecture, comparable to NVIDIA GTX 1650 Ti with FSR 2.0+ support RaceRoom runs very well on it - to my eye anyway. I have also installed Assetto Corso Competizione but I don't like it as the UI experience (while driving) isn't as smooth. I'm guessing ACC needs more graphics power? My question is - what will I gain if I use an external higher end GPU? I'm expecting ACC would look/run better. But will it make a difference to RaceRoom? I'm thinking of the AMD Radeon 7600M XT external GPU - also from GMKtec.
With a more powerful GPU you'll be able to use higher graphics settings. How much higher depends on what you use right now and what resolution and frame rate you want. But your current GPU, based on benchmarks that I looked at, seems quite fine for Raceroom.
I´d spend the money on a decent monitor instead, you´ll gert much more enjoyment out of that than on a tablet sized screen.
A few years ago I used a Ryzen APU with integrated gfx and it worked fine with Raceroom for hotlapping on my own, but as soon as there were opponents (AI or real) it was not playable anymore, fps were too low… If you haven‘t tested it I suggest you should try that before buying a new monitor